SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab076e5afd2d741f381df3948a23932eb2759b02007ac782b932942165754cbe' 
  AND token = '5O26wMnwG5dIYTza9COIxQuBh7t6jcD44sfKxu70qPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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