SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7d9ed08862947397f08aeb30c73801b8900814adf7faec0fd3a853eee769ae14' 
  AND token = 'lVeqSDzPNJ+awqbeLpHysyAvjs1zCRTYKs0m6GVLtR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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