SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f87d3856c025ebe27dfbdef8f6cd56ed5e9d2928811e2f482187ab20887aa375' 
  AND token = 'Ian+YWbjAGQpTbDx2Q8auNuR9fhTzumOBfs0aCqZy8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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