SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fad8fde59dca6cee6804f675a868198bc4527fdaf26b3a504d32bd88ab4cc07' 
  AND token = 'Jh/0HOAror3N1YCFHbbeGPlhcCAgwxXhwI6CI/+Ts2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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