SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1ceecb97e8660bba9a9c13f07d3bc4c32df667c38f59626ff030b5bd1789876' 
  AND token = 'mFpoaUrQjf7zMCVMWjJMe7Kxi2LSOMCLKoyGlXAlApo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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