SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e4467f67621abd3a66de8cf0d902fba0ab631b5003cc711fad6a17c51d63f4' 
  AND token = 'RGGF/GSY+Yu6yBTOPakktjrwxCrVS8+MXtqVbVmWKiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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