SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ada0c5b278edb475d24879194742b597b339db14de9179337ceec3f39c8fe44' 
  AND token = 'QTuXvn/NJXXPCl/I9Ys2B/N3oKYtLoUEUSY4+UpDBes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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