SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54c8638546db05a69ee80e4adff03f4cc2893d288283de36e3cffb508b86551b' 
  AND token = 'm4Cw16qUO7/BAh2I6Rb/L606pw45eGcJJ5V3tRgOq3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}