SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37a0a8ea7b822efb90af9083da361c4fd5e429138dadbdecade6a494762fe96c' 
  AND token = 'aK2I9Z+iLL0mNG/CKehkVnWjH54LH9h3lYaptMUGHMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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