SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaee369c464366cc909230e4a2249fc9373ae6432c22323cf58495e0ff023c02' 
  AND token = 'hEzzwa1yVXnrbiyIQ295kiwiCQ1Z+EhfCmgQeqxUbqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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