SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6cf0b6fe3890f8a0fe26c2b80ee1c67a00196b14085b77b50c4a009c0ccf899' 
  AND token = 'gNjp86vuMQEqRFuenwFPopkcl7urd7llLDP8db95/m0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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