SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1551609948d2e1554cabf827ef87a3c4fe8874f9023821b40b390d4be9a27ce8' 
  AND token = 'Iwu0x9oJ8w+qX6e3K5I2gHtn5SA5umqfIddWZqiMzgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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