SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89be8caeb3a3350dd48588209c1bb499c592752d0e5497e8a53289b8466fc254' 
  AND token = 'NpWWxyy8GY8K65cw6nlyqN2gHB090xSBuwrMmGozMPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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