SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ef7eccc9396e7c8511be08dbb9993831cfb577eaa95e457c209c7c0e1836900' 
  AND token = 'Cf+uBaBTilGj7ilctS4i6thZGtdkivjiPk5ChBWXCe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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