SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d063aaa343659a743795640de68fef9d304f5fc079328e4d5ae8e0f2856f51a' 
  AND token = 'kZgPlQsxad7tUyrAaO/AZaaGrUVsO8Ijqi8SAM3tu8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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