SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd84b4611ac9d98392adcb00a6c6f72e981008b88fe45e6ee07577eb0182ae110' 
  AND token = '5ytkPoYhsz8UvIFUJoPQMXM9hdbQ0pL90sQ+oqL2wrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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