SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2398fbcd79b3ccc03f4e05bb89c5103c4c5e838b15f2943afd88d65e89fe73b1' 
  AND token = 'E6DW5qUPPbpYqZoH7MzjQOXKY0RSfd+F3g0oFBOPVKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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