SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eb59535fd8301e2a0062627714eb0cd32bbc525582e53c449cef0a47791c10f' 
  AND token = 'nuInhsPbCLK7SoBF5oBKo9B3NOkEVCvN4zfBOJ0RApw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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