SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '570de18a593c1879c1dbad43885594cc2a91aa795888a38b6daf24c5df4685fa' 
  AND token = 'XqpxOKgrAZfB/l9VMg8hH8J2RHh0SocRd8a5ScfmJ5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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