SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeeed3f6ec9bfc1840654ddcda61ca9ac98f025355d457bb4696237a03efdf81' 
  AND token = 'HUKUkyM6OV2/QJmNXcmGRixPouiBGUTFQqQ8Bm7olCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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