SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f34a358df55fd4c4dd5efff465285e27fe891cb69bae382f5be0b7224eaca209' 
  AND token = 'vBuOWQyBjzlDUhqcVCuy7YBZTIMaKgiYBMArOim8Okw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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