SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb14b4df0d180f1a521463d6f18f0e7150c038f14a7c591237b9fff392adbd9e' 
  AND token = 'JDwei9DB/w6kM5r3jXeFK1uUh4CiWq2jLLtYpqgIIgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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