SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47002b2b6757f73e061290c9ebb9f481306921980b57f555c8882c9abb48350b' 
  AND token = 'ex+yeAPXpYVQ0d2cMQrkNV9pK+L3CVxRnw2pp1plnTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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