SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0964124905daa9968cbf62daf11edbd12be76f8311323e26b54fef2d510e5bd' 
  AND token = 'MIxNwhQvUJHZgQ/+75HrZeRsymIgdJJ9MC+52kUVIto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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