SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9190e6d0cc33eb8a7b29b77562022ffe7580596c0b51b3fb1db7af1a66047d21' 
  AND token = 'IHUBfnaUF31GQjqlRzvO+NChX0uBFMRmh6XMhhNzUB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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