SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fccfcb0f4409bfd83d53fd5802fdd1e160d8cdffa79a7a9f017dcc21a7f95d12' 
  AND token = 'LkIX9GYAZtAxyzagzdgQZu1hMLLYTmo20tBTV2BKsZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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