SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9248f3347aa7e1e2fe055bb4121b529a3ac416bfaa7d5008b6d205d631e80db2' 
  AND token = 'xp7Iuio+KF5djXV51n4mdevjWisMw4OzQlGyg+qtmsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}