SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fadbe3de2ededaf211a95ce72d82a7052f4d43a2ad6fef59def0b2a3c787c56' 
  AND token = 'YFV8EJzqUg3UXBROf4jDToYXRZAojMfi9EdW8YCZj28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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