SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5ba66b6d7b8e217b9cf44cffc83419a02def7ff5d1f03eb6c84e7aa00e9c5629' 
  AND token = 'hh6MoQATKQ9kwKDKGGL5IsZdiMdg3IUkwwo3r6U6vR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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