SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0335855f2f6a96d133eb4b104957ce16f8eff99ee15cfa3ec974b09cbd548f9' 
  AND token = '5ewhO1YvyovgcMXdcEUXxeE24GEmZ1LgVqJ7uXMCAr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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