SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11f910361333fc05c6422647b6f53357c8a94fd20689acf9776e2a89c54633a2' 
  AND token = 'xluMuCLhkiNJOi+6XMX99wJfQpjCTID8meTAD+POELU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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