SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80a002e4e6f8142a36647a6a0152984d381818d684547ba9c2178f75c0bdb34d' 
  AND token = 'B8gDZHhxKNPkMaGrtLl8vouxbW2qDsYkRjmRj5E3z7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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