SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8b9c9f6bf017473013690b9044d628de3cc7197808bc92da58807d82a70353b6' 
  AND token = 'VkC0iaeJARlEIDKhVDICErwHPsgAmrvFRCQUj38Q7o8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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