SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e0eb0dcc7f1f3554fbf11c35e6a502af93150571024fb29c8a82a95b4e4490e' 
  AND token = 'IalJNw8NN0aJRiZ7vuY2Jqmv+joyw9NurJHET7AwdVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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