SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f9343884ea5162dbe32a56e7f4332740868bfc5c01f074fc8914f1d6bdce63' 
  AND token = 'Rg6NP+t7YxNLzrnZA3laR5yrVrCwH4qNqZyYQPLyCaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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