SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '26c710b58df8751eb242a9586fe6cad5ffd540af65e16131cde4373d4f4e7965' 
  AND token = 'hRQUGiR5DDjvJ9EssmTs4nAuzowZpkD/1gbep4grI/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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