SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0eef99313dcd9f6ede48e88b2f04f2fba383356d37c89990b09ab5afa1e0b48' 
  AND token = 'WIo4g7rcOzY+dd4S68wyK/egYjSNOC3OH9J1CNHIFKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}