SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f55c6ce10e53cf450a398defd0bbe57094ea3ff10356ef61c73a430f9cf3c96d' 
  AND token = 'HTXxSHsJEInIi0MIZMHI1IR6q7hmOEa13NQ3Pw6nSz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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