SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be855af2df337b6505c329b14424c1ea93aa4517f14b2a174818ba1f66b09a69' 
  AND token = 'lR8Z+QDBAjABzBMlcNJi70v3mfC8/uBuoPU3aQQK+0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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