SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7684ea7c244a6297bd9af5c0bb65efd11649cf669aac5ee083434839bc1581b' 
  AND token = 'NghPCGfnY6epKOefDdhGTUSeCJ06BT8mD/InLtesRkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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