SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41a1bf2462efcd1efafe2f2fbc23022eb91f18de093bb534a0035439b136c9b' 
  AND token = 'yUx8cEkVfNpBxzp9hvvXV296gx4xJuqs7+yBh1nayEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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