SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '456340507864522e004cffd3dd687b005a78f6132983f33d241ba02255ceab87' 
  AND token = 'Ih6sXp/L6EVidLeJbKRFOhyHMvqFe3mvE4WbC09e2Ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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