SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d6e9510904d6614d6160f32f4215f373f3df750ab4ab4023fd9375a0d2f22ed' 
  AND token = 'nXuzHKSmFAL3ZD9rlvh9reGWiMO7Egl6rHHrL5t9r1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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