SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b757b87a7c20a371baeaa95f5bfaff419d882650bedac38c87a8c6fe4a2ae797' 
  AND token = 'E1C1TOu4O+gdnql75bOrRe7L2Q+YPUnw6ItSaFUJr4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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