SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2a70dbd73d4b927b1877cd46bbc05123edf6cdf962d1bae0237231f90357a69b' 
  AND token = 'MdhW2hV3P2GMRDOlMRPzMVItNvH1lMGOCK2whXXP7zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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