SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '833e4248beab0205f3600fdf165e57e2829456b420f65f35cb00a6879930518e' 
  AND token = 'HEADkyW3aC/J+ab0WvjbhX+FeoRqGCUKQcUg7n52T3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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