SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f83d88b66f3ff1c90af9b0dfc631d846d56c2ac85a328efe5ecfb34da8b70d8' 
  AND token = 'JMd6h2uzwnDycF2WnJYPxiip1fvNeLFSyA2FDgJpumo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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