SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0550e3953dd07f5e70c8e38ce91625d048aedea825e588ec1736cb4c5704db9' 
  AND token = '7SpGqEOT7rXoIPBaucf+hXub1jIknmRmNIHZuK9LEmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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