SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '976d12154b29139e5da111861acad41810b66dd4765fd238b7c00f2adc69f044' 
  AND token = 'twzBuhnHrcAERIVt3IKk1bUtTcNjjaNyLpLsYwj0tPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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