SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3231840eecb680c032d061f1eb851cd8ead2cd3ecbf34fc9065296288b205c13' 
  AND token = 'RSHMg5u/AIfdXm35Aw8keziuowKYfETVLFn2HG8Iisc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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