SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25ca481025ab44a6a1e9102771f9c99da7d5f2aa746beeaf7bfe8045ade718b' 
  AND token = 'fsV3f3GCAKigj15TeJcPzJKWWlZA5blgXHUXKHqkcxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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