SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62bf76391fbcc798aa3e769611989c992a587be75cdce1ee65cc1f39965fd8d1' 
  AND token = 'WWhZ/dal0GXKn4xwbJf3rm9yEO11bYLEh3wSBIaqix0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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