SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eb0bebd61b90e499aada172310e04944f86fc2e17987423ff36f154f085eabb' 
  AND token = 'hFJ0JyI0cmO+kfMz9yynHpnZ1fTt6GeCa1jSdQfcbAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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