SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e23ec29f640158301d02c1d4f86bd9e615250b270ba93c2590e5e44aa29e4e4' 
  AND token = 'oEPwFtZGio2Rai0WG/fazk4fT77JZuLOFfuYtUIzZaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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