SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58254d663c1a2187d1f068f9ac8867202a17eed1de70084965b7ad448d08d655' 
  AND token = 'RkVBFc75DoBWjPyoN1dP9qipOIVtvSlF8sgj/PtxOCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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