SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0523b98ae6b610b81f999efb07e63a2d47cd265b427e3fff76cd6df8d4f35fa4' 
  AND token = 'dG5VSjp9rnTZzDqEKIg5OjkVs+b5ueygFBglbSrleJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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