SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ec6ed9f72be95874ee09de3bf4b6b5c3126c37dcf5b9db1a561dd650d04d605' 
  AND token = 'VKobms488fBsz+JZ6uDhy4sB211i3tfyfzAtZ3xKMbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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