SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f570538b095537a89c20d2ed75f882290109aaa35a676af4537aec55a339c806' 
  AND token = 'aNMcDFzPRndVeb+gExFtIpgdtVvSZfRWxtP0FDNypHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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