SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9454c3f2050b68a2c3d4a17eeb6990698a057e4f7a12b585cb9e9f0bfed62d3b' 
  AND token = 'vdoUUk9II9JJFHPggKyzNyWWcNmWCE+AP4ulvZvbSeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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