SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17cd7635828a3346bab9f4544b1252f89f3fe4552e8103ad6aae688e2e8bb890' 
  AND token = '8h80cQBKLf40HG6brpXq9xGCbKkZAULjMrokmCq64FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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