SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e3eaeec112f312b44b80cf55e9ce8e9bb3ab3087e9eff369375649c7fafbd2b' 
  AND token = 'yUPpiHoeIW0GGHegEdNOYxa1umebyqm1zgPaIZysB30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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