SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78d590bd065057f1ca3aaf9d19161207b36db06f521f7ad3e9ac6170d66d9382' 
  AND token = 'qKichHPM/gpU7I+qYBCLhrsJHtdwmyVm3CYlQ0Q7LQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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