SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '792ec2cda9225e17a328b2f483fb7921dd7c8a1a8ef9194b496ddfa153713513' 
  AND token = 'pwg9i1WMMfxUjA79vaY6Gsg7vilWXCTFRyayugOOdD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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