SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acaa2a338d28bd6b2f43c5df720284901eba0b96dc9bd659e3462b14361b9f94' 
  AND token = 'ZbQf0smu7dMcIYbeGbBQjX/MW8VQZdCzB0P0Tw7RdJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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