SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25367584ef9e8375685a8c9008bbe1698c7b35d21b7edc3cffed9c3921edb687' 
  AND token = '/3S5+yKgNiFAl0CnCKg9fVhopm144CEvDsWHj1uGdxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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