SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2acdf586ada9fd0cc874cfc0eedf779453b1134315578c630a9d8fe3c0dffe6' 
  AND token = 'ylrfgKdz4hL0R00xXBIEgH0SSj+amCCFzSMygyhWXy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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